e107 web portal Referers HTTP Injection

[Chinchilla <kingchinchilla () hotmail com>]

Synopsis:

All versions of e107 have a vulnerability that
allows html tags and content to be posted to the stats
page and to be listed under Referers and may also list
a screen size that they wish.


Description:

All versions of e107 have a vulnerability that
allows html tags and content to be posted to the stats
page and to be listed under Referers and thus allowing
an attacker to put any site link or code they want on
the list of Referers.

The Problem lies within the e107 log plugin
file /e107_plugins/log/log.php as it does not parse
< > and / tags thus allowing a user to enter html
content like so:

target.com/e107_plugins/log/log.php?referer=
code<br>goes<here>
&color=24&eself=http://www.target.com/stats.php&res=1341X1341

This would print out:

code
goes
here

In the Referers list and print out a screen size of
1341x1341 with a color depth of 24.

Impact:

This could lead someone to graffiti the stats page
with content of their liking which could further lead
someone to input their account info, etc. With use
of proxies someone may also advertise their site as
the top referer.

Work-around:

The easiest way to fix this problem is to
simply turn off stats all together. Even if you edit
log.php to parse html tags people will still be able
to post text to the Referers list.